The interaction of gonococci of varying colony morphology (T1-T4 of Kellogg), piliation (T1 and T2 of Kellogg), and virulence (egg-passaged, or obtained freshly from genital discharges; i.e., with intact "virulence factor") with human polymorphonuclear leukocytes, monocytes, and macrophages will be evaluated. The effects of serum (normal vs gonorrhea-infected donors) and semen (normal donors, screened for CMV) on this interaction will be studied. The ability of gonococci to persist within cultures of human macrophages as facultative intracellular parasites, the influence of lymphocyte-stimulation products (lymphokines) on macrophage handling of the gonococcus, and the ability of macrophages to protect gonococci from extracellular antimicrobial agents will be evaluated.